Method for flash-distilling petroleum



Oct. 12, 1937. E. B. MccoNNELL METHOD FOR FLASH DISTILLING PETROLEUM Filed April 19, 1954 ETWF,

A TTORNEYS Patented Oct. `12, 1937 UNITEDSTATES METHOD Fon FLAsH-DIsTILLrNG PETROLEUM i Elliott B. McConnell, Cleveland Heights, Ohio, assignor to The Standard Oil Company, Cleveland, Ohio, a, corporation of Ohio i Application April 19, 1934, serial No. 721,338

6 Claims.

In the distillation of petroleum, it is a customary practice to heat the oil in a heating coil and discharge into a fractionating column. At the point of discharge,` vapors disengaged proceed on up the column, while liquid gathering on the plate adjacent the point Yof feed-in to the tower is'usually allowed to flow down into the liquid at the bottom of the tower, and be drawn off therewith as one of the regular side streams. I have found that the materialen this plate contains constituents which should not properly go into the rst side stream, and other constituents which should not go intol the bottoms. The mixture of these constituents is due to mechanical entrainment, l5 there being considerable turbulence in the flash Zone of this type of equipment. VIn accordance with the present invention however, it now becomes possible to attain a proper separation of such previously-mixed constituentaand an improved operation of fractionation results correspondingly. Y

To the accomplishment of the foregoing and related ends, the invention, then, comprises `the features hereinafter f ully described, and particu-V larly pointed out in the claims, the following de-` scription and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative'however, of but I `a few of the various .Ways in which the principle of the inventionmay be employed.

such as reduced crude, and its outlet connection 5 leading to a fractionating column C. The

lattericontains plates 6 which may be of conventional bell cap type, or of other detail as desired, Vcapabl-:of'providing countercurrent contact, of vapors and liquid withreux. 'Ihe `inlet connection 5 tothexfractionating column leadsA tothe lowerportion' of the column, below the lowermost plate. Above the -lowermost platejdesira'bly a suitable .distributor of superheated steam is arranged, `suchas a rosette 1 From the lowermost plate a connection 8 leads to the feed line, a receiver tank ,9 and a pump IIJ being interposed, as desired, and the connection preferably having branch'junctions II, I2, each valve-controlled, to the coil feed line 4 and to the coil-discharge line 5, respectively. Thereby, as readily seen, it

is conveniently possible to return liquid from the lowermost plate which is in the zone of turbulence tothe intake of the fractionating column, either anterior to the heating coil, or atva point be- 5 tween the heating coil and the tower, or both, according to desired temperature requirements.

A balance line I3 connecting from the top of the receiver tank 9 to the vapor space above the lowermost plate in the fractionatng column is adl0 visable if such tank 9 be employed. At the bottom of the fractionating column C, a steam inlet,

as a rosette I4 may be provided, and a drain line I5 leading through a cooler IB may serve to discharge the bottoms orV asphaltic residuum. A l5 side-stream outlet ,connection Il leads from the plate just below the superheated steam inlet, to a tank or otherV point of disposal of the cylinder stock stream, and preferably through a cooler I8.

A by-pass I9, valve-controlled,connects from-the 20 line I'I back to the lowermost plate. Other sidestream lines 2i),Y 2l, are provided, each leading to Y its respective tank or point of disposal, and preferably through coolers 22, 23. From the top of the tower, a vapor oitake 24 proceeds through 25 a preliminary condenser 25 to a barometric condenser26.;

In accordance with the process characterizing the invention, petroleum to be fractionated is passed through the heating zone or coil 2. For 30 instance, a reduced Mid-Continent crude supplied through the feed line 4 is heated to suitable flash temperature, for example 780-800 F., and is passed to the lower portion of the fractionating column'C. On discharge into the tower, vapors 35 disengag'ing proceed up through the plates, and unvaporized residue Works down countercurrently to the steam supplied at thepoint I4, and the ultimate residuum is drawn voff through line I5 and cooler I B. Refluxing condensate collecting 4o ontplate 6a. is returned by connection 8 into the feed stream, as by being pumped from the receivertank 9 through the connection II intol line 4. Where the relative volume of the reflux condensate from the plate 6a is rather large, and 45 application of additional heat is not particularly required, part or all of it may be passed through connection I2 vinto the feed 1ine-5 leading to the column. From the connection I1-at the side ofy the tower,` aside-stream of condensate of heavy 50 character in the range of cylinder stock is taken 0E through cooler I8. A side-stream of Vcondensate of the character of wax slopV is taken 01T through connection 20 Vat the side of the tower and proceeds through cooler 22 to a receiving tank 55 Y barometric condenser 2B and the remainder of the condensing system. Steam is supplied, generally superheated steam, at the rosette 1, and bottom steam as desired, at the rosette I4.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, providedthe features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:-

l. A process of distilling petroleum which comprises the steps of heating a stream of petroleum oil in a heating zone, discharging such heated stream into a fractionating zone, whereby a zone of turbulence is created adjacent the heated oil inlet, separating the vaporous materials from the heavy unvaporized liquid, passing vapors through and into intimate contact with a body of oil within said zone of turbulence, whereby undesirable color and tarry materials are removed from said vapors, further fractionating the vapors to separate and withdraw from the system a heavy lubricating oil fraction, said fraction being withdrawn from a point adjacent said body of oil and being free of undesirable color and tarry material, removing a portion of said body of oil and recycling said portion, together with the petroleum oil back to said fractionating Zone.

2. A process Volf distilling petroleum which comprises the steps of heating a stream of petroleum oil in a heating zone, discharging such heated stream into a fractionating Zone, whereby a zone of turbulence is created adjacent the heated oil inlet, separating the vaporous materials from the heavy unvaporized liquid, passing vapors through and into intimate contact with a body of oil within said Zone of turbulence, whereby undesirable color and tarry materials are removed from said vapors, further fractionating the vapors to separate and withdraw from the system a heavy lubricating oil fraction, said fraction being withdrawn from a point adjacent said body of oil and being free of undesirable color and tarry material, removing a portion of said body of oil and recycling said portion, together with the petroleum oil through said heating zone and back to said fractionating zone.

3. A process of distilling petroleum which comprises the steps of heating a stream of petroleum oil in a heating zone, discharging such heated stream into a fractionating zone, whereby a Zone of turbulence is created adjacent the heated oil inlet, separating the vaporous materials from the heavy unvaporized liquid, passing vapors through and into intimate contact with a body of oil within said Zone of turbulence, whereby undesirable color and tarry materials are removed from said vapors, further fractionating the vapors to separate and Withdraw from the system a heavy lubricating oil fraction, said fraction ybe ing withdrawn from a point adjacent said body of oil and being free of undesirable color and tarry material, removing a portion of said body of oil and recycling said portion, together with the petroleum oil from said heating zone and back to said fractionating zone.

4. A process of distilling petroleum which comprises the steps of heating a stream of petroleum oil in a heating zone, discharging such heated stream into a fractionating zone, whereby a zone of turbulence is created adjacent the heated oil inlet, separating the vaporous materials from the heavy unvaporized liquid, passing vapors through and into intimate contact with a body of oil within said zone of turbulence, whereby undesirable color and tarry materials are removed from said vapors, further fractionating the vapors to separate and withdraw from the system a heavy lubricating oil fraction, said fraction being withdrawn from a point adjacent said body of oil and being free of undesirable color and tarry material, removing a portion of said body of oil and recycling said portion, together with the petroleum oil in the initial stream of petroleum and partially with the oil of the heated stream back to said fractionating zone.

5. A process of distilling petroleum which comprises the steps of heating a stream of petroleum oil in a heating zone, discharging such heated stream into a fractionating zone, whereby a Zone of turbulence is created adjacent the heated oil inlet, separating the vaporous materials from the heavy unvaporized liquid, passing vapors through and into intimate contact with a body of oil within said zone of turbulence, whereby undesirable color and tarry materials are removed yfrom said vapors, further fractionating the vapors toseparate and withdraw from the system a heavy lubricating oil fraction, said fraction being withdrawn from a point adjacent said body of oil and being free of undesirable color and tarry material, removing a portion of said body of oil and recycling said portion, together with the petroleum oil back to said fractionating Zone and'still further fractionating said vapors in Zones above the point of withdrawal of said heavy lubricating oil fraction, to obtain lighter condensates.

6. A process of distilling petroleum which comprises the steps of heating a stream of petroleum oil in a heating zone, to a temperature of from about 780 to about 800 F., discharging such heated stream into a fractionating Zone, whereby a zone of turbulence is created adjacent the heated oil inlet, separating the vaporous materials from the heavy unvaporized liquid, passing vapors through and into intimate contact with a body of oil within said zone of turbulence, whereby undesirable color and tarry materials are removed from said vapors, further fractionating theY vapors to separate and withdraw from the system a heavy lubricating oil fraction, said fraction being Withdrawn from a point adjacent said body of oil and being free of undesirable color and tarry material, removing a portion of said body of oil and recycling said portion, together withthe petroleum oil back to said fractionating zone.

ELLIOTT B. MCCONNELL. 

